Sonic pressure wave generator



Feb. 1, 1966 N. HUGHES SONIC PRESSURE WAVE GENERATOR Filed Feb. 25, 1963 INVENTOR.

United States Patent 3,232,267 SONIC PRESSURE WAVE GENERATOR Nathaniel Hughes, Bronx, N.Y., assignor to Sonic Development Corporation of America, Yonkers, N.Y.

Filed Feb. 25, 1963, Ser. No. 260,737

, 1 Claim. (U. 116-137) This invention relates to apparatus for generating pressure waves in fluids; and, more particularly, to improved apparatus utilizing the flow of gases to generate sonic pressure waves in gaseous media.

The sonic pressure wave generator of the present invention constitutes an improvement over the inventions disclosed in my co-pending applications for United States Patent Serial Nos. 239,236, filed on November 21, 1962, and 247,221, filed on December 26, 1962, which applications are hereby incorporated in and made an integral part of this description.

Broadly, sonic generators in accordance with the abovementioned co-pending applications utilize a pressurizedgas-supplied nozzle having a diverging exit region to create a high-speed, low-pressure, gas jet which is directed into a cavity pulsator to create a sonic pressure wave output. Although the performance of such generators is substantially greater than that of generators previously available, the generator of the present invention provides even further improved performance.

Accordingly, an object of this invention is to provide a novel and improved gas-operated sonic pressure wave generator which produces more sonic pressure wave power output with a given pressurized gas input than previous sonic generators.

A further object of this invention is to provide such a generator which is inexpensive to manufacture, operate and maintain.

The drawings and description that follow describe the invention and indicate some of its uses and advantages.

In the drawings:

FIGURE 1 is a perspective view of a sonic pressure wave generator embodying the present invention; and

FIGURE 2 is a vertical section view of this generator taken along line 2-2 of FIGURE 1, in the direction of the arrows.

Referring to FIGURES 1 and 2 of the drawings, the sonic generator shown includes a nozzle housing member, generally indicated at 10, which comprises a tubularshaped section 12 connected to a pair of leg-like members 14 terminating in a pointed, comically-shaped end portion 16 containing a pulsator cavity 18 with its open end facing toward tubular member 12.

A cylindrical nozzle member, generally indicated at 29, is mounted inside nozzle housing member with its forward end abutting under-cut portions of the rear ends of legs 14 (see FIGURE 2). Nozzle member 20 has a converging inlet section 22, a cylindrical middle or stabilizing section 24, and a diverging outlet section 26. A source of pressurized gas (not shown) is connected to tubular portion 12 of nozzle housing It Pressurized gas flows from the supply through nozzle 20 and emerges in the form of a gas jet which is intercepted by pulsator cavity 18. When thus energized, the unit develops a highly concentrated core of sonic pressure wave energy in the region between the exit of nozzle 20 and pulsator cavity 18 in the manner described in my above-mentioned co-pending patent applications. Powerful sonic pressure waves then spread outwardly from this intense core of energy.

When constructed and operated in accordance with the above-mentioned patent applications, the nozzle 20 produces a gas jet having a Mach number appreciably greater than 1.0 and preferably greater than 1.6. The nozzle also produces at its exit a pressure appreciably less than "ice the pressure of the ambient gas surrounding the nozzle and preferable less than 1 or 2 pounds per square inch absolute (p.s .i.a.). In order to attain these flow characteristics, the ratio of the cross-sectional area of the nozzle exit opening of divergent section 26 to the cross-sectional area of the stabilizing section 24 is made appreciably greater than 1 to l and preferably 1.5 to 1 or greater. The substantial difference between the pressure at theexit of the nozzle and the pressure at the exit of the nozzle and the pressure of the ambient gas causes the ambient gas to be drawn in or imploded into the intense sonic energy core produced in the region between the exit of nozzle 29 and the entrance of pulsator cavity 18. As is more fully described in my above-mentioned patent applications, this implosion greatly enhances the power output and efiiciency of the sonic generator.

The improvement added by the present invention comprises the provision of a tapered, pointed shape for endportion 16 of nozzle housing 10. End portion 16 is preferably given a conical shape with a pointed tip 28 which is directed away from nozzle member 20. It has been found that, when end portion 16 is given such a shape and is so positioned, the generator produces more power for a given pressurized gas input pressure than produced by previous sonic generators, and, therefore, is more efficient and economical to use than previous generators.

It is believed that this improvement in performance is obtained because the tapered, pointed shape of end portion 16 of nozzle housing 10 increases the rate at which ambient gas is drawn or imploded into the core of sonic energy. It has been found that part of the imploding gas flows rearwardly, that is, in a direction opposite to the flow of the jet issuing from nozzle 20. Thus, much of this rearwardly flowing gas passes over the surface of tapered end 16. The pointed taper of this end portion 16 increases the velocity of the ambient gas flowing over it and, therefore, increases the rate at which it is delivered to the sonic energy core. In addition, the increased velocity of this gas lowers the pressure at the surface of tapered end 16 and draws inwardly toward tapered end 16 the gases flowing in a forward direction from the sonic energy core so that these gases flow more freely and do not interfere with the flow of the inrushing implosion gas into other regions of the core.

Although a specific preferred embodiment of the invention has been set forth in detail, it is desired to emphasize that this is not intended to be exhaustive or necessarily limitative; on the contrary, the showing herein is for the purpose of illustrating the invention and thus enabling those skilled in the art to adapt the invention in such ways as meet the requirements of particular applications, it being understood that various modifications may be made without departing from the scope of the invention.

I claim:

A gas-operated pressure wave generator, said generator comprising, in combination, a gas-accelerating nozzle comprising a body member forming a gas flow passageway, first, second and third longitudinal positions in said body member, said second position being spaced from said first position in the direction of flow of gas through said nozzle, and said third position being spaced from said second position in the direction of flow of gas through said nozzle, restrictor means reducing the cross-sectional area of said gas flow passageway and forming a reduced orifice at said first longitudinal position, stabilizing means in said gas flow passageway between said reduced orifice and said second longitudinal position, said stabilizing means providing a substantially constant cross-sectional area for said passageway between said reduced orifice and said second longitudinal position, said stabilizing means also providing another orifice at said second longitudinal position, said other orifice having a cross-sectional area substantially equal to that of said reduced orifice,

expansion means in said gas flow passageway between said other orifice and said third longitudinal position, said expansion means providing an increasing cross-sectional area for said passageway between said other orifice and said third longitudinal position in the direction of flow of gas through said nozzle, resonator means, and means for positioning said resonator means adjacent the exit opening of said gas flow passageway, said resonator means comprising a resonator member with a front surface, a resonator cavity in said front surface, and a rear external surface which is tapered to a point, said resonator member being positioned by said positioning means with said cavity facing said nozzle exit and the pointed end of said tapered rear surface extending away from said nozzle.

References Cited by the Examiner UNITED STATES PATENTS 4/1922 Good 116-137 X 7/1923 Bliss 116-137 X 10/1930 Negro 239601 4/1934 Roselund 15873 11/1934 Amy 116137 6/1936 Huss 158-73 9/1936 Frisk 84-330 10/1942 Stephanoff 116-137 12/1944 Lee 15877 8/1950 Yellott et a1 116-137 12/1957 Pesce 239-73 11/1961 Straughn et a1. 117100 l1/1962 Fortrnan 116- 137 10/1963 Solofi 116-137 FOREIGN PATENTS 12/1931 France.

6/1915 Germany.

Great Britain.

LOUIS J. CAPOZI, Primary Examiner. 

